Method of making bearing sleeves



Dec 27, 1932' B. sTocKs-LETH METHOD. oF MAKING BEARING sLEEvEs AFiled. Jam.- 2, 1931 Patented Dec. 27, 1932 'UNITED STATES PATENT OFFICE BERGER STOCKFLETH, OF NILES, MICHIGAN, ASSIGNOR, BY MESNE ASSIGNMENTS, TO

THE CLEVELAND GRAPHITE BRONZE COMPANY, F CLEVELAND, OHIO, A. CORPORA- TION 0F OHIO METHOD OF MAKING-BEARING SLEEVES Appneation ined Janary 2, 1931. serial No. 506,196.

This invention relates to improvements in means and methods for making bi-metallic articles, such as lined bea-ring sleeves.

Such a sleeve consists of a relatively harder metal backing shell, such as steel, and a relatively softer bearing metal lining, such as Babbitt metal, and the invention relates particularly to improvements in the so-called pressure method of making or finishing such j suitable bonding coating, such as tin; l This layer of bearing metal whichis preferably Babbitt metal, is also roughly of the linished dimensions but is preferably also thicker radially and shorter circumferentially and longitudinally than in the finished sleeve.

The sleeve blank thus provided, which is preferably less than a half cylinder, is placed in a die having a die opening of the shape and dimensions of the outer surface of the iinished sleeve.l and a (ro-operating plunger is provided, the co-operating operative end of which has the shapeand dimensions of the inner surface of the finished sleeve. The die and plunger are so related that the ends of the die space are closed While at the longitudinal sides the space is open.

The plunger is forced intp the die, thereby compressing the rough sleeve between the plunger and the die, and pressure is applied suiiicient to cause the lining and the back to be thinned radially and elongated circumferentially. ncidentall'the sleeve is also elongated longitudinally. The amount of metal in the blank is preferably more than suilicient to form the finished sleeve, even when compressed` and the excess is forced out, that is, extruded through the' openings or slots at the sides. VThe result of the application of the heavy pressure applied is that the rough bearing is shaped and sized accurately within the allowable tolerance and the sleeve is thereby completed except for the removal of the extruded portions along the longitudinal edges of the shell.

Preferably, the rough sleeve is heated to a temperature at which the bearing metal is malleable before being placed in the press, and also the dies may be maintained at a temperature preferably slightly less than the melting point of the bonding metal. The preheating of the rough sleeves and the heating ofthe dies both assist in the perfection of the bond between the metals of the sleeves and in the reduction of the power used in the pressing operation.

The invention will be best understood by reference to the accompanying drawing forming part of this specification and in which A Fig. 1 is a perspective view of a half-cylindrical hearing sleeve illustrating an article to which my invention applies and with parts broken away to best illustrate the invention;

Fig. 2 is an enlarged fragmentary section e `showing a. sleeve in position to be pressed;

Fig. i-is an enlarged view similar to Fig. 3, idllustrating the finish of the pressing step; an

Fig. 5 is an enlarged transverse section of the nished sleeve similar to the section shown in Fig. 4.

In said drawing, 1 illustrates a half cylindrical bearing comprising a backing shell 2 of harder metal, such as steel, brass or bronze, and an inner lining 3 of bearing metal, such as Babbitt metal.

- The lining 3 is bonded to the inner surface of the back. Preferably, in order to make this bond as perfect as possible, the inner surface of the back 'shell is roughened and bright clean metal is presented over its whole inner surface, as indicated at 4. Then this surface, at least, of the back is tinned preferably by first dipping the back into a suitable acid bath to clean the back, then into a pot of melted tin. The tin coating on the inside which is very thin is indicated at 5.

After the back is thus prepared, the Babbitt metal lining is added by some method 5 which causes it to be bonded to the back opening 7 of the shape and dimensions of the outer or convex surface of the finished bearing, and 9 is a plunger having a lower end 10 for co-operation with the die member 6 to form the inner or concave surface 11 of the nished sleeve. The end 10 of the plunger 9 is accurately of the size and form desired for the inner concave surface 11 of the finished sleeve.

As shown in Fig. 3, the rough sleeve is preferably not quite a half circle, as indicated by the clearance spaces 12at its edges.

Preferably, as stated, the rough sleeves are pre-heated to a tem erature approximately the melting point o the bonding metal be'- fore they are placed in the press and the dies are preferably maintained at approximately the same temperature by any suitable means, such as electrically heated elements 13 arranged in suitable openings 14 in the die members 6 and 9.

The pressure method of sizing and finishing the bearing sleeve consists in subjecting the rough sleeves to an enormous pressure radially in suit-able dies, such as those shown at 6 and 9, sufficient to actually'compress and thin the sleeve radially and cause it to be squeezed out and elongated circumferentially. Such manipulation of the sleeve in the forming pressure results in many advantageous features.

Both the lining and the backing are compressed beyond their respective elastic limits and are consequently more solid or dense than before the operation. This is of benefit in causing the bearing sleeve to transmit heat more effectively outwardly in use, resulting in a cooler running' bearing. This com ression ofthe metal ofthe sleeve goes far eyond any compressive forces to which it may be subjected to in use', and consequently the sleeve is more permanent in form.

Furthermore, by such 4pressure method the sleeves are accurately sized within the allowable tolerance land they ordinarily-do not .A need any sizing by any cutting or machining methods.

- The bearing metal, such as Babbitt metal,

proving the bond between the lining and the back but, so far as I am aware, none of these methods have satisfactorily withstood the strain incident to the pressure method of forming and finishing. By means of this present method, however, I am enabled to attain a substantially perfect bond between the back and the lining in bearing sleeves finished by the pressure method.

In applying forming pressure to the sleeve by the die and punch method illustrated, it is obvious that when pressure is applied sufficient to cause the lining metal to be squeezed out of the die space through the longitudinal slots 12 between the sides of the die and plunger, that there will be more or less drag on the backing shell and if this drag can be vmade great enough, the two parts will be substantially equally elongated circumferentially. I increase this drag by two vmeans; first,

by the very thorough roughening and clean-` ing of the inside of the` backing shell preferably by what is known as the shot blasting or deep etching; and second, by making the lining of Babbitt metal relatively thin, and applying-it in such a manner that 1t is not only mechanically bondedr to the back through its roughened surface, but also molecularly bonded through the medium of the bonding metal as explained, preferably tin. f Such thorough and complete bonding of the lining to the back, especially when the lining is'relatively thin, results in the substantially equal elongation of the back and the lining, and no mechanical means is necessary to prevent the advance or excess extruslon of the lining metal.

A relative proportion as to thickness between the back and lining which has proven successful in this method is substantially 1 to '3 or'more, that is, the lining is substantially one third or less as thick as the back.

As illustrated in Fig. 4, the lining metal maybe extruded to a slight degree faster than the back, as illustrated by the outwardly curved extruded portions 15, but thisl is not y sufficient to disrupt the bond between the lining and the back. l

To complete the bearing sleeve, these extruded parts 15 are removed by any suitable method, as indicated by the dotted lines in -Fig 5.

Unless some hindering means are provided, the softer bea-ring metal will be thinned out and extruded in advance of the back-ing metal.

Albv

There are two causes tending to prevent the advance thinning and extrusion of" the Babbitt metal; these are the drag of the bearing metal on the plunger and the dra of the bearing metal on the back. The metal which lies between the outer and inner surfaces of the lining will be .held against extrusion by the molecular forces in the lining metal as augmented by the drag on the inner and outer surfaces of the lining, consequently, l make the lining relatively thin and thus prevent the advance extrusion of the lining metal to any substantial extent.

I In other words, I so proportion the thickness of the lining and back that the two metals are substantially equally extruded from the dies. It is to be understood, of course, that a thorough'mechanical bonding of the lining to the Jback as well as a bonding by means of 1. The herein described method of making hin a suitable bonding metal is an advantage in obtainin the results desired.

It has heenfound in practice that ifthe linthe backing metal,

The invention resldesin a bearing sleeveV blank having a harder metal back and* a bearing metal lining bonded to the back `and so proportioned in thickness .tofthe thickness .of the back that when the blank is subjected to radial vpressure in suitable forming dies for the purpose of sizing and iinishing the sleeve,

-t-he lining is not thinned'toV 'any substantial extentin advance of the back but for all practicable purposes the back and lining are simultaneously thinned.

The invention also resides in the herein described pressure method of forming` and sizing bi-metal bearing sleeves andwhich includes .the provision of blanks for formation by the pressure method, the blank comprising harder metal backs and bearing met-al linings bonded thereto and so .proportioned as to thickness that the drag of the lining on the forming plunger and on the back shell to which it is bonded is sufficient to prevent any,

a bi-metal bearing sleeve of the kind described, which consists in first making a bi;

metal blank forthe sleeve, the blank consisting of a harder, tougher metal back and a earing is not more -than approximately 3/64 thick it will not Abe extrudedA in advance of metal.

within the scope of the appendedfclaims. A

ly thereto in suitable dies, to thin the sleeve radially and cause substantially equal elongation of the metals of the sleeve in a direc-v tion substantiall parallel to the die surfaces.

2. The inventlon as deiined in claim l the elongation of the metals being most pronounced in a circumferential direction.

3. The invention as defined in claim 1, the space between the dies provided with an outlet permitting extrusion of the surplus material, the outlet being so placed and large enough so that both the lining and the back will be extruded therethrough, and the lining and back so proportionedl as to thickness that they are substantially equally extruded.

4: The herein described method of making bearing sleeves which includes the provision of a substantially half-cylindrical roughly sized blank, consisting of a relatively harder,

tougher metal back and a relatively softer and more ductile bearing metal lining, and ressing the blank between suitable die memers, the applied pressure being sufficient to thin the sleeve radially and elongate it in a direction Vsubstantially parallel with the die surface, and the bearing metal lining being thin enough so that the two metals. are substantially equally elongated.

5. The herein described method of making a bi-metal bearing sleeve of the kind described, which consists in first making a bi'- metal blank .for the sleeve roughly formed to shape and consisting of a back of harder toughermetal suchas steel, and a bearing metal lining secured tothe back by asuitable bonding'metal, heating the blank to approximately the melting point Lof the ,bonding l metal, and` subjecting the sleeve, in such heated condition, t pressure applied subl stantially radially thereto, the applied pressure being suficient to cause the sleeves to be thinned radially and the substantially equal elongation of the metals of the sleeve. substantially parallel with the die surfaces.

6. The invention as defined in claim 'and maintaining the dies heated to approximatelyI the melting temperature of the bonding In testimony whereof, I' have hereunto set.V

` my hand this fteenth day of December, 1930,

BERGER SirooKFLn'rH.'

relatively softer bearing metal lining, the

lining both mechanically and moleclarly f i bonded to the back and the lining being rela# l,

tively thin and subjecting the blanktosuf- .e cient pressure appliedzsubstantially radial- 

